A powerful household water purification system offers the cleaning power of an industrial water treatment plant into a container the size of a ketchup packet, researchers announced.

The researchers said that they have demonstrated that the tiny packet, which acts as a chemical filter, can be added to contaminated water to dramatically reduce pathogen-induced diarrhea -- the top killer of children in much of the developing world.

The packets also show promise for boosting water safety during emergencies and natural disasters, such as earthquakes, floods and hurricanes, where water purity is suddenly compromised, according to researchers the researchers. The packets were described on March 29 at the 231st national meeting of the American Chemical Society.

Worldwide, approximately 1.5 million children under age five die each year from simple diarrhea acquired from pathogens found in drinking water, according to public health experts. That translates to about 4,000 children dying each day as a result of contaminated water.

"This is a tragedy that can be prevented," said Greg Allgood, PhD (allgood.gs@pg.com), director of Procter & Gamble's Children's Safe Drinking Water program, which manufactures the packets. The company has been developing the packets since 1995 in collaboration with the U.S. Centers for Disease Control and Prevention (CDC).

In those countries that lack a modern water purification system, boiling is often the main water decontamination method, Allgood said. But boiling must be done properly to remain effective. In many parts of the world, drinking water is not cleaned at all, he added.

"There's clearly a need for simple, safe and effective decontamination systems for Third World countries," Allgood said. Unlike large stationary purification systems, the packets are small and portable, which allows them to be easily used in remote locations and emergency situations. "This tiny system seems to fit that bill by quickly providing high water quality that can rival that of a modern treatment plant."

In randomized, controlled trials conducted by the CDC involving a total of 25,000 people in three countries -- Guatemala, Pakistan and Kenya -- the chemical packets reduced the incidence of diarrhea by about 50 percent, Allgood said. The packets also were tested by researchers from Johns Hopkins University at a refugee camp in Liberia, where they produced more than a 90 percent reduction in diarrhea, the scientist said.

Called "PUR Purifier of Water," the system consists of a packet containing a grayish powder composed of a variety of chemicals that collectively are capable of removing contaminates within minutes of being added to water. The main active ingredients of the powder are calcium hypochlorite (bleach), which can kill a wide range of deadly pathogens, and ferric sulfate, a particle binder that can remove impurities such as dirt and also disease-causing pathogens that aren't killed by the bleach. The packets can kill water-born pathogens that cause cholera, typhoid and dysentery; remove a variety of toxic metals, including lead, arsenic and mercury; and also remove dangerous pesticides like DDT and PCB, Allgood said.

A single packet can decontaminate 2.5 gallons of drinking water, or enough drinking water to sustain a typical household for about 2-3 days, Allgood said. The packet is added to a large container of impure water, stirred, filtered through a cloth to remove impurities and then allowed to sit for 20 minutes. The net result is clear, safe drinking water, the researcher said.